Negative pressure is required at ink ejection nozzles of inkjet printheads so that undesired ink ejection or leakage is prevented when the nozzles are not being operated to print. Ink supply arrangements to ink ejection nozzles which provide such negative pressure are known. U.S. Pat. No. 4,422,084 discloses several examples of such ink supply arrangements. One of the disclosed arrangements positions a spring within an ink tank which regulates the collapse of the ink tank. However, each of the disclosed arrangements and other conventional arrangements do not provide constant negative pressure at the nozzles. As a result, some ink ejection or leakage may still occur.